O-sulfated β-lactam hydroxamic acids and intermediates

ABSTRACT

Antibacterial activity is exhibited by β-lactams having a sulfate substituent in the 1-position and an acylamino substituent in the 3-position.

RELATED APPLICATION

United States patent application Ser. No. 188,893, filed Sept. 29, 1980,ABN discloses β-lactam antibiotics having a sulfonic acid salt(SO₃.sup.⊖ M.sup.⊕) substituent in the 1-position and an acylaminosubstituent in the 3-position.

BACKGROUND OF THE INVENTION

The β-lactam ring, ##STR1## has been known since the late nineteenthcentury. While knowledge of β-lactam chemistry developed during theearly 1900's, it was not until 1929 that Fleming reported in Brit. J.Exper. Pathol., 10, 226 (1929) that a fermentation product of theorganism Penicillium notatum had antibiotic properties. The compoundwhich Fleming had worked with was benzylpencillin, ##STR2## The in vivoactivity of benzylpenicillin against various bacteria was reported byChain et al. in Lancet, 2:226 (1940).

During the early 1940's research in the field of penicillins wasintense. This research focused first on structure elucidation and thenon synthetic routes for preparing benzyl penicillin. It was not,however, until the late 1950's that a totally synthetic route wasdiscovered for the preparation of benzyl penicillin.

U.S. Pat. No. 2,941,955, issued June 21, 1960, to Doyle et al.,discloses the discovery of 6-aminopenicillanic acid, ##STR3## Thispatent was followed by U.S. Pat. No. 2,951,839, issued Sept. 6, 1960,also to Doyle et al., which discloses the use of 6-aminopenicillanicacid as a valuable intermediate which could be acylated, usingart-recognized procedures, to obtain penicillin derivatives havingantibiotic properties. Using 6-aminopenicillanic as a stepping stone,research chemists have prepared numerous penicillin derivatives havingantibiotic activity.

The second major class of β-lactam antibiotics is the cephalosporins. Inthe 1940's a Cephalosporium species was found to produce an antibioticthat had activity against gram-positive and gram-negative bacteria. Workin the 1950's showed that the fermentation product of a Cephalosporiumspecies contained not one, but several antibiotics. One of theseantibiotics, cephalsporin C, ##STR4## proved to be an important steppingstone in cephalosporin research. Removal of the acyl group in the7-position of cephalosporin C yields 7-aminocephalosporanic acid,##STR5## an intermediate useful for the preparation of numerous acylatedcompounds which are analogs of cephalosporin C.

The penicillins and cephalosporins are, of course, the most important ofthe β-lactam antibiotics reported to date. Others have, however, beenreported. Stapley et al., Antimicrobial Agents and Chemotherapy,2(3):122 (1972) disclose that certain actinomycete cultures isolatedfrom soil produce antibiotics characterized by a methoxy group andD-α-aminoadipic acid on the 7-carbon of the cephem nucleus. Thecephamycins, as they are known, have the formula ##STR6## Stapley et al.reported that cephamycin A and cephamycin B each exhibits a similarrange of potencies against gram-negative and gram-positive bacteria, andcephamycin C had greater potency against gram-negative bacteria thanagainst gram-positive bacteria. Cephamycin C was reported to be the mostactive of the three antibiotics.

Scannell et al., The Journal of Antibiotics, XXVIII(1):1 (1975),disclose the isolation from a fermentation broth of Streptomyces species372A of(S)-alanyl-3-[α-(S)-chloro-3-(S)-hydroxy-2-oxo-3-azetidinyl-methyl]-(S)-alanine,which has the formula ##STR7##

The structure of the above naturally occurring monocyclic β-lactamcontaining molecule is similar to the structure of the earlierdiscovered β-lactam containing molecules known as tabotoxins, i.e.,##STR8## wherein X is hydrogen or methyl as reported by Stewart, Nature,229:174 (1971), and Taylor et al., Biochem. Biophys. Acta., 286:107(1972).

Recently, several novel series of naturally occurring β-lactamantibiotics have been isolated. The nocardicins, nocardin A and B, aremonocyclic β-lactams having the formula ##STR9## as reported byHashimoto et al., The Journal of Antibiotics, XXIX (9):890 (1976).

Clavulanic acid, a bicyclic β-lactam antibiotic isolated fromfermentation broths of Streptomyces clavuligerus, has the formula##STR10## i.e., Z-(2R,5R)-3-(β-hydroxyethylidene)-7-oxo-4-oxa-1-azabicyclo[3,2,0]heptane-2-carboxylicacid, as reported by Lloyd et al., J.C.S. Chem. Comm., 266 (1976).

Still another recently isolated β-lactam antibiotic is thienamycin, anantibiotic isolated from the fermentation broths of Streptomycescattleya. As reported by Albers-Schonberg et al., J.A.C.S., 100:20, 6491(1978), thienamycin has the structure ##STR11##

Additional fused β-lactams, olivanic acid derivatives, have recentlybeen isolated from cultures of Streptomyces olivaceus. As disclosed byBrown et al., J.C.S. Chem.Comm., these olivanic acid derivatives havethe formulas ##STR12## The isolation of the above antibiotics, and adiscussion of their activity, is reported by Butterworth et al., TheJournal of Antibiotics, XXXII(4):294 (1979) and by Hood et al., TheJournal of Antibiotics, XXXII(4):295 (1979).

Another recently isolated β-lactam antibiotic is PS-5, reported byOkamura et al., The Journal of Antibiotics, XXXI: 480 (1978) and TheJournal of Antibiotics, XXXII(4):262 (1979). The structure of thisantibiotic, which is produced by Streptomyces cremeus subspeciesauratilis, is reported to be ##STR13## Structurally related antibioticsPS-6 and PS-7 are reported in European Patent Application Ser. No. 1,567to have the respective structures ##STR14##

BRIEF DESCRIPTION OF THE INVENTION

This invention is directed to a novel family of β-lactam antibiotics,and to the use of such compounds as antibacterial agents. It has beendiscovered that the β-lactam nucleus can be biologically activated by asulfate (--O--SO₃.sup.⊖ M.sup.⊕) substituent attached to the nitrogenatom in the nucleus.

β-Lactams having a sulfate substituent in the 1-position and anacylamino substituent in the 3-position exhibit activity against a rangeof gram-negative and gram-positive bacteria.

The preferred members of the novel family of β-lactam antibiotics ofthis invention are those encompassed by the formula ##STR15##

In addition to the above described β-lactams having a sulfatesubstituent in the 1-position and an acylamino substituent in the3-position, this invention also encompasses β-lactams having a sulfatesubstituent in the 1-position and an amino (NH₂) substituent in the3-position. The preferred compounds of this type have the formula##STR16## These compounds are intermediates useful for the preparationof corresponding 3-acylamino compounds.

As used in formulas I and Ia, and throughout the specification, thesymbols are as defined below.

R₁ is acyl;

R₂ is hydrogen or alkoxy of 1 to 4 carbons;

R₃ and R₄ are the same or different and each is hydrogen or alkyl; and

M.sup.⊕ is hydrogen or a cation, with the proviso that if M.sup.⊕ ishydrogen the 3-substituent contains a basic function.

Listed below are definitions of various terms used to describe theβ-lactams of this invention. These definitions apply to the terms asthey are used throughout the specification (unless they are otherwiselimited in specific instances) either individually or as part of alarger group.

The terms "alkyl" and "alkoxy" refer to both straight and branched chaingroups. Those groups having 1 to 10 carbon atoms are preferred.

The terms "cycloalkyl" and "cycloalkenyl" refer to cycloalkyl andcycloalkenyl groups having 3,4,5,6 or 7 carbon atoms.

The term "alkenyl" refers to both straight and branched chain groups.Those groups having 2 to 10 carbon atoms are preferred.

The term "halogen" refers to fluorine, chlorine, bromine and iodine.

The term "protected carboxyl" refers to a carboxyl group which has beenesterified with a conventional ester protecting group. These groups arewell known in the art; see, for example, U.S. Pat. No. 4,144,333, issuedMar. 13, 1979. The preferred protected carboxyl groups are benzyl,benzhydryl and t-butyl esters.

The term "acyl" includes all organic radicals derived from an organicacid (i.e., a carboxylic acid) by removal of the hydroxyl group. Certainacyl groups are, of course, preferred, but this preference should not beviewed as a limitation of the scope of this invention. Exemplary acylgroups are those acyl groups which have been used in the past to acylateβ-lactam antibiotics including 6-aminopenicillanic acid and derivativesand 7-aminocephalosporanic acid and derivatives; see, for example,Cephalosporins and Penicillins, edited by Flynn, Academic Press (1972),German Offenlegungsschrift No. 2,716,677 published Oct. 10, 1978,Belgian Pat. No. 867,994, published Dec. 11, 1978, U.S. Pat. No.4,152,432, issued May 1, 1979, U.S. Pat. No. 3,971,778, issued July 27,1976, U.S. Pat. No. 4,172,199, issued Oct. 23, 1979, and British Pat.No. 1,348,894, published Mar. 17, 1974. The portions of these referencesdescribing various acyl groups are incorporated herein by reference. Thefollowing list of acyl groups is presented to further exemplify the term"acyl"; it should not be regarded as limiting that term. Exemplary acylgroups are:

(a) Aliphatic groups having the formula ##STR17## wherein R₅ is alkyl;cycloalkyl; alkoxy; alkenyl; cycloalkenyl; cyclohexadienyl; or alkyl oralkenyl substituted with one or more halogen, cyano, nitro, amino,mercapto, alkylthio, or cyanomethylthio groups.

(b) Carbocyclic aromatic groups having the formula ##STR18## wherein nis 0, 1, 2 or 3; R₆, R₇, and R₈ each is independently hydrogen, halogen,hydroxyl, nitro, amino, cyano, trifluoromethyl, alkyl of 1 to 4 carbonatoms, alkoxy of 1 to 4 carbon atoms or aminomethyl; and R₉ is amino,hydroxyl, a carboxyl salt, protected carboxyl, formyloxy, a sulfo salt,a sulfoamino salt, azido, halogen, hydrazino, alkylhydrazino,phenylhydrazino, or [(alkylthio)thioxomethyl]thio.

Preferred carbocyclic aromatic acyl groups include those having theformula ##STR19## (R₉ is preferably a carboxyl salt or sulfo salt) and##STR20## a carboxyl salt or sulfo salt).

(c) Heteroaromatic groups having the formula ##STR21## wherein n is 0,1, 2 or 3; R₉ is as defined above; and R₁₀ is a substituted orunsubstituted 5-,6- or 7-membered heterocyclic ring containing 1, 2, 3or 4 (preferably 1 or 2) nitrogen, oxygen and sulfur atoms. Exemplaryheterocyclic rings are thienyl, furyl, pyrrolyl, pyridinyl, pyrazinyl,thiazolyl, morpholinyl, pyrimidinyl and tetrazolyl. Exemplarysubstituents are halogen, hydroxyl, nitro, amino, cyano,trifluoromethyl, alkyl of 1 to 4 carbon atoms, or alkoxy of 1 to 4carbon atoms.

Preferred heteroaromatic acyl groups include those groups of the aboveformulas wherein R₁₀ is 2-amino-4-thiazolyl, 2-amino-5-halo-4-thiazolyl,4-aminopyrimidin-2-yl, 5-amino-1,2,4-thiadiazol-5-yl, 2-thienyl or2-furanyl.

(d) [[(4-Substituted-2,3-dioxo-1-piperazinyl)carbonyl]amino]arylacetylgroups having the formula ##STR22## wherein R₁₁ is an aromatic group(including carbocyclic aromatics such as those of the formula ##STR23##and heteroaromatics as included within the definition of R₁₀); and R₁₂is alkyl, substituted alkyl (wherein the alkyl group is substituted withone or more halogen, cyano, nitro, amino or mercapto groups),arylmethyleneamino (i.e., --N═CH--R₁₁ wherein R₁₁ is as defined above),arylcarbonylamino (i.e., ##STR24## wherein R₁₁ is as defined above) oralkylcarbonylamino.

Preferred[[(4-substituted-2,3-dioxo-1-piperazinyl)carbonyl]amino]arylacetylgroups include those wherein R₁₂ is ethyl phenylmethyleneamino or2-furylmethyleneamino.

(e) (Substituted oxyimino)arylacetyl groups having the formula ##STR25##wherein R₁₁ is as defined above and R₁₃ is hydrogen, alkyl, cycloalkyl,alkylaminocarbonyl, arylaminocarbonyl (i.e., ##STR26## wherein R₁₁ is asdefined above) or substituted alkyl (wherein the alkyl group issubstituted with 1 or more halogen, cyano, nitro, amino, mercapto,alkylthio, aromatic group (as defined by R₁₁), carboxyl (including saltsthereof), amido, alkoxycarbonyl, phenylmethoxycarbonyl,diphenylmethoxycarbonyl, hydroxyalkoxyphosphinyl, dihydroxyphosphinyl,hydroxy (phenylmethoxy)phosphinyl, or dialkoxyphosphinyl substituents).

Preferred (substituted oxyimino)arylacetyl groups include those whereinR₁₁ is 2-amino-4-thiazolyl. Also preferred are those groups wherein R₁₃is methyl, ethyl, carboxymethyl, or 2-carboxyisopropyl.

(f) (Acylamino)arylacetyl groups having the formula ##STR27## whereinR₁₁ is as defined above and R₁₄ is ##STR28## amino, alkylamino,(cyanoalkyl)amino, amido, alkylamido, (cyanoalkyl)amido, ##STR29##

Preferred (acylamino)arylacetyl groups of the above formula includethose groups wherein R₁₄ is amino, or amido. Also preferred are thosegroups wherein R₁₁ is phenyl or 2-thienyl.

(g) [[[3-Substituted-2-oxo-1-imidazolidinyl]carbonyl]amino]arylacetylgroups having the formula ##STR30## wherein R₁₁ is as defined above andR₁₅ is hydrogen, alkylsulfonyl, arylmethyleneamino (i.e., --N═CH--R₁₁wherein R₁₁ is as defined above), ##STR31## (wherein R₁₆ is hydrogen,alkyl or halogen substituted alkyl), aromatic group (as defined by R₁₁above), alkyl or substituted alkyl (wherein the alkyl group issubstituted with one or more halogen,cyano, nitro, amino or mercaptogroups).

Preferred[[3-substituted-2-oxo-1-imidazolidinyl]carbonyl]amino]arylacetyl groupsof the above formula include those wherein R₁₁ is phenyl or 2-thienyl.Also preferred are those groups wherein R₁₅ is hydrogen, methylsulfonyl,phenylmethyleneamino or 2-furylmethyleneamino.

The term "cation", as used throughout the specification, refers to anypositively charged atom or group of atoms. The "--O--SO₃.sup.⊖ M.sup.⊕ "substituent on the nitrogen atom of the β-lactams of this inventionencompasses all sulfate salts. Pharmaceutically acceptable salts are, ofcourse, preferred, although other salts are also useful in purifying theproducts of this invention or as intermediates for the preparation ofpharmaceutically acceptable salts. The cationic portion of the sulfonicacid salts of this invention can be obtained from either organic orinorganic bases. Such cationic portion includes, but is not limited to,the following ions: ammonium; substituted ammonium, such asalkylammonium (e.g., tetra-n-butylammonium, referred to hereinafter astetrabutylammonium); alkali metal, such as lithium, sodium andpotassium; alkaline earth metal, such as calcium and magnesium;pyridinium; dicyclohexylammonium; hydrabaminium; benzathinium;N-methyl-D-glucaminium.

As set forth in formula I, and in the definitions following formula I,M.sup.⊕ can be hydrogen provided the R₁ group contains a basic function.Such compounds are often referred to in the art as "inner salts" byvirtue of a positive and negative charge in the molecule.

Some of the compounds of this invention may be crystallized orrecrystallized from solvents containing water. In these cases water ofhydration may be formed. This invention contemplates stoichiometrichydrates as well as compounds containing variable amounts of water thatmay be produced by processes such as lyophilization.

β-Lactams having a sulfate substituent in the 1-position and an amino oracylamino substituent in the 3-position contain at least one chiralcenter--the carbon atom (in the 3-position of the β-lactam nucleus) towhich the amino or acylamino substituent is attached. This invention isdirected to those β-lactams which have been described above, wherein thestereochemistry at the chiral center in the 3-position of the β-lactamnuclues is the same as the configuration at the carbon atom in the6-position of naturally occurring penicillins (e.g., penicillin G) andas the configuration at the carbon atom in the 7-position of naturallyoccurring cephamycins (e.g., cephamycin C).

With respect to the preferred β-lactams of formulas I and Ia, thestructural formulas have been drawn to show the stereochemistry at thechiral center in the 3-position. Because of the nomenclature convention,those compounds of formulas I and Ia wherein R₂ is hydrogen have theS-configuration and those compounds of formulas I and Ia wherein R₂ isalkoxy have the R configuration.

Also included within the scope of this invention are racemic mixtureswhich contain the above-described β-lactams.

DETAILED DESCRIPTION OF THE INVENTION

β-Lactams having a sulfate (--O--SO₃.sup.⊖ M.sup.⊕) substituent in the1-position and an acylamino substituent in the 3-position have activityagainst a range of gram-negative and gram-positive organisms. Thesulfate substituent is essential to the activity of the compounds ofthis invention.

The compounds of this invention can be used as agents to combatbacterial infections (including urinary tract infections and respiratoryinfections) in mammalian species, such as domesticated animals (e.g.,dogs, cats, cows, horses, and the like) and humans.

For combating bacterial infections in mammals a compound of thisinvention can be administered to a mammal in need thereof in an amountof about 1.4 mg/kg/day to about 350 mg/kg/day, preferably about 14mg/kg/day to about 100 mg/kg/day. All modes of administration which havebeen used in the past to deliver penicillins and cephalosporins to thesite of the infection are also contemplated for use with the novelfamily of β-lactams of this invention. Such methods of administrationinclude oral, intravenous, intramuscular, and as a suppository.

The β-lactams of this invention can be prepared from the correspondinghydroxamic acid having the formula ##STR32## A compound of formula IIcan be O-sulfated by reacting the precursor compound with a complex ofpyridine and sulfur trioxide. The reaction can be run in an organicsolvent, preferably pyridine. This reaction yields a compound of formulaI wherein M.sup.⊕ is pyridinium ion. Instead of using a pre-formedcomplex of pyridine and sulfur trioxide, the complex can be formed insitu, e.g., using chlorosulfonyltrimethylsilyl ester and pyridine asreagents. Alternatively, a complex of dimethylformamide sulfur trioxideor 2,6-lutidine-sulfurtrioxide can be used.

Using conventional techniques (e.g., ion-exchange resins,crystallization, or ion-pair extraction) the pyridinium salt formed bythe above procedure can be converted to other salts. These techniquesare also useful for converting the products of formula I or any of theintermediates described herein to other salts.

Compounds of formula II can be prepared from an amino acid having theformula ##STR33## The amino group is first protected with a classicalprotecting group (e.g., t-butoxycarbonyl, benzyloxycarbonyl,o-nitrophenylsulfenyl, etc.), yielding a compound having the formula##STR34## In formula IV, and throughout the specification, the symbol"A" refers to a nitrogen protecting group.

The carboxyl group of a protected amino acid of formula IV is thenreacted with an amine salt having the formula

    Y-O-NH.sub.3.sup.⊕ Cl.sup.⊖,

In formula V, and throughout the specification, the symbol "Y" refers tobenzyl or pivaloyl. The reaction proceeds in the presence of a couplingagent such as 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide ordicyclohexylcarbodiimide, and yields a compound having the formula##STR35## The hydroxyl group of a compound of formula VI is converted toa leaving group, using, for example, a classical reagent such asmethanesulfonyl chloride (methanesulfonyl is referred to hereinafter as"Ms").

The fully protected compound having the formula ##STR36## is cyclized bytreatment with base, e.g., potassium carbonate. The reaction ispreferably carried out in an organic solvent such as acetone, underreflux conditions, and yields a compound having the formula ##STR37##

Alternatively, cyclization of a compound of formula VI can beaccomplished without first converting the hydroxyl group to a leavinggroup. Treatment of a compound of formula VI with triphenylphosphine anddiethylazodicarboxylate, yields a compound of formula VIII.

Both of the methods disclosed above for ring closure of a compound offormula VI result in the inversion of the stereochemistry of the R₃ andR₄ substituents.

Deprotection of the 3-amino substituent of a compound of formula VIIIcan be accomplished using art-recognized techniques. If, for example,the protecting group is t-butoxycarbonyl, trifluoroacetic acid can beused to deprotect the amino group. If the protecting group isbenzyloxycarbonyl catalytic (e.g., palladium on charcoal) hydrogenationcan be used. If the protecting group is o-nitrophenylsulfenyl,p-toluenesulfonic acid can be used in combination with p-thiocresol. Thedeprotected compound has the formula ##STR38##

Well known acylation techniques can be used to convert a compound havingthe formula IX to a compound having the formula ##STR39## Exemplarytechniques include reaction with a carboxylic acid (R₁ -OH) orcorresponding carboxylic acid halide or carboxylic acid anhydride. Thereactions with a carboxylic acid proceed most readily in the presence ofa carbodiimide such as dicyclohexylcarbodiimide and a substance capableof forming a reactive intermediate in situ such asN-hydroxybenzotriazole or 4-dimethylaminopyridine. In those instanceswherein the acyl group (R₁) contains reactive functionality (such asamino or carboxyl groups) it may be necessary to first protect thesefunctional groups, then carry out the acylation reaction, and finallydeprotect the resulting product.

Conversion of a compound of formula X to the corresponding compoundhaving a 3-alkoxy substituent can be accomplished by first halogenatingthe amide nitrogen to obtain a compound having the formula ##STR40##Reagents and procedures for N-chlorinating amides are known in the art.Exemplary reagents are tert.-butyl hypochlorite, sodium hypochlorite,and chlorine. The reaction can be run in an organic solvent (e.g., alower alkanol such as methanol) or in a two phase solvent system (e.g.,water/methylene chloride) in the presence of a base such as sodiumborate decahydrate. The reaction is preferably run at a reducedtemperature.

Reaction of a compound of formula XI with an alkoxylating agent, e.g.,an alkali metal alkoxide, yields a compound (in combination with itsenantiomer) having the formula ##STR41## The reaction can be run in anorganic solvent, e.g., a polar organic solvent such as tetrahydrofuran,at a reduced temperature.

Alternatively, a compound of formula X can be converted to a compound offormula XII using a single step procedure. The alkoxylating agent canfirst be mixed with a compound of formula X and the N-chlorinatingreagent then added to the reaction mixture.

Reduction of a compound of formula X or XII to yield the correspondingcompound of formula II, i.e., ##STR42## can be accomplished by catalytichydrogenation or, if Y is pivaloyl, by treatment with a base such assodium sulfide or sodium hydroxide.

Alternatively, α-benzyloxycarbonyl-β-aminoxy-D-alanine, methyl esterhydrochloride, or other compounds having the "NH--O--" grouping, can beused in place of an amine salt of formula V in the above describedsynthesis.

An alternative synthesis for the compounds of this invention wherein R₂is hydrogen comprises preparation of a compound of formula VIII followedby deprotection of the 1-hydroxy group of that compound to yield acompound having the formula ##STR43## Deprotection can be accomplishedusing art-recognized procedures, e.g., if Y is pivaloyl, treatment withhydrogen peroxide and a base or treatment with sodium sulfide, or if Yis benzyl, by hydrogenolysis.

Sulfation of a compound of formula VIIIa using the above-describedprocedures (i.e., reaction of the precursor compound with a complex ofpyridine and sulfur trioxide, dimethylformamide and sulfur trioxide or2,6-lutidine and sulfur trioxide) yields a compound having the formula##STR44## Removal of the protecting group "A" from a compound of formulaXIII yields a key intermediate having the formula ##STR45## Thetechnique used for removal of the protecting group will depend on theparticular protecting group. For example, if A is benzyloxycarbonyl,catalytic hydrogenation can be used.

Acylation of an intermediate of formula XIV using any of the techniquesdescribed above yields a corresponding product of formula V wherein R₂is hydrogen.

The following examples are specific embodiments of this invention.

EXAMPLE 1 (3S-trans)-4-Methyl-2-oxo-3-[(phenylacetyl)amino]-1-azetidinylsulfate, pyridine salt (A) N-(Phenylacetyl)-L-threonine

L-Threonine (35.7 g) is dissolved in 1 N sodium hydroxide (1 liter) andchilled to -5° to -10° C. To the cold, mechanically stirred solution isadded dropwise phenylacetyl chloride (46.3 g). The reaction mixture isstirred for about 16 hours as the temperature rises to 26° C. Themixture is washed with ether, acidified to pH 2 with hydrochloric acid,and extracted with ethyl acetate (two times). The combined extracts aredried over sodium sulfate and concentrated under reduced pressure untilcrystalline solids form. Ether is added to the mixture and the crystalsare collected (34.8 g); melting point 161°-163° C.

(B) N² -(Phenylacetyl)-N-(phenylmethoxy)-L-threoninamide

N-(Phenylacetyl)-L-threonine (9.5 g) is suspended in water(approximately 50 ml), and a solution of O-benzylhydroxylaminehydrochloride (7.04 g) in water (50 ml) is added. The pH of the stirredmixture is adjusted to 4.2 with 1 N potassium hydroxide, and a solutionof 8.43 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloridein water (50 ml) is added. The pH is maintained at 4.2 with 1 Nhydrochloric acid. After thirty minutes an oily precipitate is presentin the reaction vessel. The product is partitioned between ethyl acetateand brine, and the organic layer is then dried over sodium sulfate andconcentrated to a solid (8.7 g).

(C) (3S-trans)-4-Methyl-3-(phenylacetyl)-1-(phenylmethoxy)-2-azetidinone

To a cold (0° C.) solution of N²-(phenylacetyl)-N-(phenylmethoxy)-L-threoninamide (7.5 g) in drytetrahydrofuran (200 ml) is added diethylazodicarboxylate (4.2 g)followed by triphenylphosphine (6.34 g). The reaction mixture is stirredfor about 16 hours at 26° C. under nitrogen. The solvent is thenremoved, and the residue chromatographed on silica gel (ether/hexane) toafford the title compound (2.0 g) white solids. Recrystallization fromchloroform/hexane affords a purified sample, melting point 97°-99° C.

(D) (3S-trans)-1-Hydroxy-4-methyl-3-[(phenylacetyl)-amino]-2-azetidinone

A solution of(3S-trans)-4-methyl-3-(phenylacetyl)-1-(phenylmethoxy)-2-azetidinone(0.5 g) in ethanol (15 ml) containing 0.250 of 10% palladium on charcoalis hydrogenated at 26° C. for one hour. The reaction mixture isfiltered, the catalyst washed with ethanol, and the combined filtratesevaporated to an oily residue. Ether (approximately 10 ml) is added andthe resulting solids are hardened and collected yielding 0.34 g of thetitle compound, melting point 118°-135° C., dec.

Anal. Calc'd. for C₁₂ H₁₄ N₂ O₃ : C, 61.52; H, 6.02; N, 11.96. Found: C,61.06; H, 6.03; N, 11.80.

(E) (3S-trans)-4-Methyl-2-oxo-3-[(phenylacetyl)-amino]-1-acetidinylsulfate, pyridine salt

To a solution of(3S-trans)-1-hydroxy-4-methyl-3-[(phenylacetyl)amino]-2-azetidinone(0.225 g) in dry pyridine (9 ml) is added molecular sieves 4 A (1 ml)followed by pyridinesulfur trioxide complex (0.61 g). The reactionmixture is stirred under nitrogen for five hours at 26° C., filtered andconcentrated under reduced pressure. Purification on HP-20 resin(water/acetone) affords 0.13 g of the product as a hygroscopic solid.

Anal. Calc'd. for C₁₇ H₁₉ N₃ O₆ S.H₂ O: C, 49.62; H, 5.14; N, 10.21; S,7.79. Found: C, 50.37; H, 5.07; N, 10.32; S, 7.73.

EXAMPLE 2[3S-[3α(R*),4β]]-3-[[[[(4-Ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]-4-methyl-2-oxo-1-azetidinylsulfate, pyridine salt (1:1) (A) 2-Nitrophenylthio-L-threonine

L-threonine (11.9 g) is added to dioxane (125 ml) and 2 N sodiumhydroxide (50 ml). To the vigorously stirred solution,o-nitrophenylsulfenyl chloride (20.9 g) is added in ten equal portionsover fifteen minutes, while 2 N sodium hydroxide (60 ml) is slowly addeddropwise. After five more minutes the reaction mixture is diluted withwater (400 ml) and acidified to pH 2.5 with 10% potassium bisulfate. Theorganic layer is immediately extracted with ethyl acetate (three 200 mlportions), and the combined extracts are dried over sodium sulfate, andthen concentrated to an oil. The product crystallizes on scratching(20.0 g). Recrystallization of 17 g from acetone/hexane affords 9.5 g ofcrystals, melting point 145°-148° C. which are stored in a freezer andused promptly.

(B) N² -[(2-Nitrophenyl)thio]-N-(phenylmethoxy)-L-threoninamide

2-Nitrophenylthio-L-threonine (39.0 g) and O-benzylhydroxylaminehydrochloride (22.92 g) are suspended in water (500 ml) and withvigorous stirring the pH is adjusted to 4.2 with 1 N sodium hydroxide. Asolution of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloridein water (100 ml) is added portionwise, while the pH is controlled at4.2 with addition of 10% potassium bisulfate. The addition lasts fiveminutes, and stirring and pH control is continued for an additionalthirty minutes, whereupon a heavy granular precipitate is present. Thereaction mixture is extracted with ethyl acetate (four 300 ml portions)and the combined extracts are dried over sodium sulfate and concentratedto an oil (approximately 50 g).

Chromatography on SilicAR CC-7 (2 kg, methylene chloride→50% methylenechloride/ethylacetate) affords the produce as a foam (19.5 g). A portionis crystallized and recrystallized from acetone/hexane to provide ananalytical sample, melting point 130°-133° C.

(C)(3S-trans)-4-Methyl-3-[[(2-nitrophenyl)thio]amino]-1-(phenylmethoxy)-2-azetidinone

To a cold solution (0° C.) of N²-[(2-nitrophenyl)thio]-N-(phenylmethoxy)-L-threoninamide (9.4 g) inpyridine (34 ml) is added methanesulfonyl chloride (8.58 g). After twohours at 0° C. the mixture is poured into ice water (100 ml) andextracted with ethyl acetate (five 100 ml portions). The extracts arewashed with ice-cold 10% potassium bisulfate (four 100 ml portions),dried over sodium sulfate, and concentrated under reduced pressurewithout heat, yielding 9.6 g of a residue.

A solution of the residue in acetone (125 ml), is added dropwise overthirty-five minutes to a refluxing mixture of anhydrous potassiumcarbonate (10 g) and acetone (approximately 600 ml). After 2.5 hours themixture is cooled to 26° C. filtered, and evaporated to a foam.Chromatography on SilicAR CC-7 (methylene chloride/hexane 9:1→methylenechloride) affords the product as a clear oil (2.15 g). Crystallizationand recrystallization from chloroform/hexane produces an analyticalsample, melting point 97°-100° C.

(D) (3S-trans)-3-Amino-4-methyl-1-(phenylmethoxy)-2-azetidinone,toluenesulfonate

To a stirred solution of(3S-trans)-4-methyl-3-[[(2-nitrophenyl)thio]amino]-1-phenylmethoxy)-2-azetidinone(1.07 g) in methylene chloride (20 ml) is added p-toluenesulfonic acid(0.57 g) and p-thiocresol (0.74 g). The reaction mixture is stirredunder nitrogen for two hours, whereupon the solvents are removed invacuo, and the residue is triturated with ether (four 25 ml portions),to afford 0.9 g of the title compound.

(E)(3S-trans)-3-[[[[(4-Ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]-4-methyl-1-(phenylmethoxy)-2-azetidinone

A suspension ofα-[[(4-ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]benzeneacetic acid(0.879 g) hydroxybenzotriazole (0.42 g), and dicyclohexylcarbodiimide(0.56 g), in dimethylformamide (15 ml) is stirred at 26° C. for onehour, at which point a solution of(3S-trans)-3-amino-4-methyl-1-(phenylmethoxy)-2-azetidinone,toluenesulfonate (0.95 g) and diisopropylethylamine (0.44 ml) indimethylformamide (5 ml) is added. The reaction mixture is stirred atroom temperature for about 16 hours, then poured into water (100 ml) andextracted with ethyl acetate (three 100 ml portions). The combinedorganic extracts are washed with water (three 100 ml portions) andaqueous sodium bicarbonate solution (one 100 ml portion), then driedover sodium sulfate and concentrated under reduced pressure to asemi-solid residue. Liquid chromatography (ethyl acetate) affords thedesired product as a foam (0.599 g). Recrystallization fromchloroform/isopropyl ether yields the title compound, melting point100°-105° C.

(F)(3S-trans)-3-[[[[(4-Ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]-1-hydroxy-4-methyl-2-azetidinone

(3S-trans)-3-[[[[(4-ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]-4-methyl-1-(phenylmethoxy)-2-azetidinone(0.270 g) is dissolved in ethanol (25 ml) and hydrogenated over 10%palladium on charcoal catalyst (130 mg) for two hours. The reactionmixture is filtered and concentrated to a solid (0.220 g).

(G)[3S-[3α(R*),4β]]-3-[[[[(4-Ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]-4-methyl-2-oxo-1-azetidinylsulfate, pyridine salt (1:1)

To a solution of(3S-trans)-3-[[[[(4-ethyl-2,3-dioxo-1-piperazinyl)carbonyl]amino]phenylacetyl]amino]-1-hydroxy-4-methyl-2-azetidinone(0.220 g) in pyridine (7 ml) is added 4 A molecular sieves(approximately 1 ml) and pyridine-sulfur trioxide complex (0.33 g).After stirring under nitrogen at 26° C. for 4.5 hours, the reactionmixture is filtered and concentrated to an oil. Chromatography on HP 20AG resin (water/acetone) followed by lyophilization of the appropriatefractions affords the desired product as a powder (0.080 g).

Anal. Calc'd. for C₁₉ H₂₃ N₅ O₉ S.C₅ H₅ N.2H₂ O: C, 47.05; H, 5.26; N,13.72. Found: C, 46.36; H, 4.74; N, 13.42.

EXAMPLE 3[3S(Z)]-3-[[(2-Amino-4-thiazolyl)(methoxyimino)acetyl]amino]-2-oxo-1-azetidinylsulfate, potassium salt (A) α-[(Phenylmethyl)oxy]-β-aminoxy-D-alaninemethyl ester hydrochloride

Hydrogen chloride gas is bubbled into ice cold methanol (200 ml) fortwenty minutes. α-[(Phenylmethyl)oxy]-D-cycloserine (5.0 g) is added,and the cloudy solution is stirred at 26° C. for twelve hours. Thereaction mixture is filtered and concentrated into a semisolid residuewhich upon titration with ether (two 200 ml portions) gives 4.6 g ofsolid, melting point 110°-112° C.

[A more quantitative alternative procedure comprises preparation of ca.1 N methanolic hydrogen chloride solution by adding 7.1 ml acetylchloride dropwise to 100 ml of chilled, stirred, methanol. After thirtyminutes, α-[(phenylmethyl)oxy]cycloserine (5.0 g) is added, the mixtureis evaporated after 12 hours, and the residue is triturated with ether.The resulting crystalline mass is collected by filtration and dried invacuo yielding 5.7 g of the title compound.]

(B) N²-[[(Phenylmethyl)oxy]carbonyl]-N-[2-[[[(phenylmethyl)oxy]carbonyl]amino]-3-methoxy-3-oxopropoxy]-L-serinamide

To a suspension of N-[[(phenylmethoxy]oxy]carbonyl]-L-Serine (3.46 g) inwater (15 ml), is added an aqueous (15 ml) solution ofα-[(phenylmethyl)oxy]-β-aminoxy-D-alanine methyl ester hydrochloride(4.49 g). The mixture is vigorously stirred (air stirrer), whileadjusting to pH 4.2 with 1 N potassium hydroxide. A solution of1-ethyl-3-(3-dimethylaminopropyl)carbodiimide in water (10 ml) is addedportionwise over five minutes, while the pH is maintained at 4.2 byaddition of 1 N hydrochloric acid. After stirring for an additionaltwenty minutes, the reaction mixture is saturated with sodium chlorideand extracted with ethyl acetate (five times). The combined ethylacetate extracts are dried over sodium sulfate and concentrated underreduced pressure to a viscous oil (5.8 g).

(C) (3S)-1-Hydroxy-3-[[[(phenylmethyl)oxy]carbonyl]amino]-2-azetidinone

To a cold (0°-5° C.) solution of N²-[[(phenylmethyl)oxy]carbonyl]-N-[2-[[[(phenylmethyl)oxy]carbonyl]amino]-3-methoxy-3-oxopropoxy]-L-serinamide(6.08 g) in distilled tetrahydrofuran (100 ml) is addedtriphenylphosphine (3.6 g) followed by diethylazodicarboxylate (2.15 ml,2.38 g). The reaction mixture is allowed to stir for twelve hours undernitrogen, whereupon 7.0 ml of 1,8-diazabicyclo[5.4.0.]undecan-7-ene isadded. After 30 minutes, tetrahydrofuran is removed by evaporation andthe resulting residue is partitioned between ethyl acetate and saturatedsodium bicarbonate. The aqueous layer is washed once with ethyl acetate,then adjusted to pH 2 with saturated potassium bisulfate, and extractedwith ethyl acetate (five times). The combined extracts are dried andconcentrated to a crystalline solid (1.8 g). A portion is recrystallizedfrom acetone/hexane (two times) to give an analytical sample, meltingpoint 128°-131° C.

(D) (3S)-3-[[[(Phenylmethyl)oxy]carbonyl]amino]-2-oxo-1-azetidinylsulfate, tetrabutylammonium salt

To a solution of(3S)-1-hydroxy-3-[[[(phenylmethyl)oxy]carbonyl]amino]-2-azetidinone (1.1g) in dry pyridine (45 ml) containing 4 A molecular sieves (ca. 1 ml) isadded pyridine-sulfur trioxide complex (1.48 g). After stirring for twohours at 26° C., under nitrogen, the pyridine is removed under reducedpressure, and the residue is partitioned between pH 4.3 buffer (0.5 Mmonobasic potassium phosphate, 50 ml) and ethyl acetate (50 ml). Theaqueous layer is washed once more with ethyl acetate (50 ml), thentreated with tetrabutyl ammonium hydrogen sulfate (1.57 g), andextracted with methylene chloride (three 50 ml portions). The combinedorganic extracts are dried over sodium sulfate and concentrated to aviscous oil (1.81 g). The material is purified on SilicAR CC-4 usingmethylene chloride/methanol (1% to 8%) as eluant to afford 0.71 g ofoil.

(E)[3S(Z)]-3-[[(2-Amino-4-thiazolyl)(methoxyimino)acetyl]amino]-2-oxo-1-azetidinylsulfate, potassium salt

A solution of(3S)-3-[[[(phenylmethyl)oxy]carbonyl]amino]-2-oxo-1-azetidinyl sulfate,tetrabutylammonium salt (0.70 g) in dimethylformamide is hydrogenatedfor 6.5 hours using 10% palladium on charcoal catalyst (0.35 g). Afterfiltration to remove catalyst,(Z)-2-amino-α-(methoxyimino)-4-thiazoleacetic acid (0.251 g)dicyclohexylcarbodiimide, followed by hydroxybenzotriazole (0.191 g) areadded to the mixture and it was stirred for about 16 hours at 26° C. Thereaction mixture is concentrated under high vacuum (40° C.), dilutedwith acetone (25 ml), and then filtered. The solids are washed with asmall amount of acetone and the combined filtrate is treated with asolution of potassium perfluorobutane sulfonate (0.425 g) in acetone (2ml). Precipitation occurs at once. Ether (20 ml) is added and theprecipitated solids are collected by filtration (0.250 g). Purificationby HP-20AG chromatography using water-acetone (0-5%) as eluant gives theproduct as a powder after lyophilization (0.045 g).

Anal. Calc'd. for C₉ H₁₀ N₅ S₂ O₇ K: C, 26.79; H, 2.50; N, 17.36; S,15.89; K, 9.69. Found: C, 29.63; H, 3.16; N, 16.95; S, 17.69; K, 1.78.

The product is a mixture of the potassium salt and zwitterion, anddisplays appropriate IR and NMR spectra.

EXAMPLE 4 (S)-2-Oxo-3-[(phenylacetyl)amino]-1-azetidinyl sulfate,pyridine salt (A) N² -(Phenylacetyl)-N-[(phenylmethyl)oxy]-L-serinamide

N-Phenylacetyl-L-serine (8.8 g), 1-hydroxybenzotriazole hydrate (6.03 g)and o-benzylhydroxylamine (4.84 g) are dissolved in tetrahydrofuran (450ml) and chilled to 0° C. A solution of dicyclohexylcarbodiimide (8.1 g),in tetrahydrofuran (50 ml) is added over a 0.5 hour period. The reactionis allowed to warm to 26° C. and stir for about 16 hours. The mixture isfiltered, and the filtrate concentrated under reduced pressure to asemi-solid residue. The addition of ethyl acetate (50 ml) causescrystallization. The solids are collected and dried (6.9 g, meltingpoint 150°-151° C.).

The filtrate is washed with sodium bicarbonate, water, potassiumbisulfate, and water (twice), and then dried over sodium sulfate andconcentrated until a second crop of crystals is obtained (2.6 g),melting point 131°-135° C.

(B) (S)-3-[(Phenylacetyl)amino]-1-[(phenylmethyl)oxy]-2-azetidinone

To a cold solution (0° C.) of N²-(phenylacetyl)-N-[(phenylmethyl)oxy]-L-serinamide (6.88 g) in distilledtetrahydrofuran (300 ml), under nitrogen, is added triphenylphosphine(11.20 g) followed by diethylazodicarboxylate (6.60 ml). The solution isallowed to warm to 26° C. and stirred for twelve hours. After removal ofsolvent under reduced pressure the resulting residue is applied to asilica gel column (eluant ether/hexane→ether). Combination of fractionsgives two batches; 1.0 g (pure) and 2.5 g (ca. 60% pure) (total yieldca. 2.2 g). The pure material is recrystallized from ethylacetate/hexane to give solids; melting point 130°-131° C.

(C) (S)-1-Hydroxy-3-[(phenylacetyl)amino]-2-azetidinone

To an ethanolic (100 ml) solution of(S)-3-[(phenylacetyl)amino]-1-[(phenylmethyl)oxy]-2-azetidinone (0.8 g,contaminated with triphenylphosphine) is added 10% palladium on charcoalcatalyst (0.4 g) and the mixture is hydrogenated under ca. 1 atompressure for one hour. The reaction mixture is filtered throughprewashed Celite and concentrated under reduced pressure to an oilyresidue. The product is partitioned between 50% sodium bicarbonatesolution and ethyl acetate. The aqueous layer is acidified withpotassium bisulfate and extracted with ethyl acetate (three 50 mlportions). The combined extracts are dried over sodium sulfate andconcentrated to a crystalline solid (ca. 200 mg). Recrystallization frommethanol/chloroform affords an analytical sample, melting point145°-146° C. dec.

(D) (S)-2-Oxo-3-[(phenylacetyl)amino]-1-azetidinyl sulfate, pyridinesalt

(S)-1-Hydroxy-3-[(phenylacetyl)amino]-2-azetidinone (0.150 g) isdissolved in dry pyridine (10 ml) containing 4A molecular sieves.Pyridinesulfur trioxide complex (0.216 g) is added and the solution isstirred under nitrogen for two hours. After concentration under reducedpressure, and vacuum drying, the product is purified on HP-20AG (25 ml).Elution with water and then 5% acetone/water, followed by lyophilizationof the desired fractions affords the product (0.110 g) as a hygroscopicpowder; [α]_(D) ²⁶ =+5.9 (c=0.645, water).

Anal. Calc'd. for C₁₆ H₁₇ N₃ O₆ S.0.5 H₂ O: C, 49.15; H, 4.74; N, 10.71;S, 8.34. Found: C, 49.47; H, 4.67; N, 10.81; S, 8.25.

EXAMPLE 5 (S)-2-Oxo-3-[(phenylacetyl)amino]-1-azetidinyl sulfate,potassium salt

(S)-2-Oxo-3-[(phenylacetyl)amino]-1-azetidinyl sulfate, pyridine salt(1.5 g; see example 4) is dissolved in water and applied to a columncontaining 150 ml Dowex 50-X2K resin. Elution with 1500 ml doubledistilled water gives five 300 ml fractions which are lyophilized.Fraction 1 contains 1.33 g of the title compound.

Anal. Calc'd. for C₁₁ H₁₁ N₂ O₆ S.K.1.5 H₂ O: C, 36.15; H, 3.86; N,7.66; S, 8.77; K, 10.70 Found: C, 36.14; H, 3.15; N, 7.20; S, 9.81; K,14.01

EXAMPLE 6 (S)-2-Oxo-3-[(phenylacetyl)amino]-1-azetidinyl sulfate,tetrabutylammonium salt

(S)-2-Oxo-3-[(phenylacetyl)amino]-1-azetidinyl sulfate, potassium salt(93 mg, see example 5) is dissolved in water (5 ml) andtetrabutylammonium hydrogen sulfate (102 mg) is added. The solution isshaken for a few minutes, saturated with sodium chloride and extractedwith methylene chloride (four times). The combined extracts are driedover sodium sulfate and concentrated under reduced pressure to an oil(112 mg).

Anal. Calc'd. for C₁₁ H₁₁ N₂ O₆ S.C₁₆ H₃₆ N: C, 59.85; H, 8.74; N, 7.75;S, 5.91. Found: C, 60.25; H, 9.40; N, 7.13; S, 5.51.

EXAMPLE 7 (S)-2-Oxo-3-[(2-thienylacetyl)amino]-1-azetidinyl sulfate,potassium salt

A solution of(3S)-3-[[[(phenylmethyl)oxy]carbonyl]amino]-2-oxo-1-azetidinyl sulfate,tetrabutylammonium salt (1.0 g; see example 3D) in dimethylformamide (20ml) containing 10% palladium on charcoal (0.5 g) is hydrogenated for sixhours at 26° C. The mixture is filtered to remove catalyst.Hydroxybenzotriazole (0.261 g) is added, followed by thiopheneaceticacid (0.243 g) and finally dicyclohexylcarbodiimide DCC (0.352 g). Thereaction mixture is stirred at 26° C. for about 16 hours, and thenconcentrated at 40° C. under high vacuum. The residue is diluted withacetone (10 ml) and the resulting precipitate is filtered and washedwith acetone (2 ml). To the acetone filtrate is added potassiumperfluorobutane sulfonate (0.867 g) in acetone (2 ml). The solution istreated with ether (approximately 30 ml) and the precipitate is filteredand dried in high vacuum. Chromatography on HP-20 resin (water→5%acetone/water) affords the product after lyophilization as a solid (51mg). This material contains approximately 50% potassium perfluorobutanesulfonate.

Anal. Calc'd. for C₉ H₉ O₆ N₂ S₂ K: C, 31.38; H, 2.63; N, 8.14; S,18.62; K, 11.55. Found: C, 22.58; H, 1.30; N, 4.17; S, 14.63; K, 8.62.

In an attempt to further purify this material, the substance isdissolved in a small amount of acetone and ether is added. Theprecipitate is collected, dissolved in water and lyophilized. Thefiltrate is evaporated, dissolved in water and lyophilized. Theprecipitate gives 13 mg of 60% pure product and the filtrate yields 16mg of 44% pure product.

EXAMPLE 8(3S-trans)-3-[(2,6-Dimethoxybenzoyl)amino]-4-methyl-2-oxo-1-azetidinylsulfate, pyridine (1:1) salt (A)(3S-trans)-3-[(2,6-Dimethoxybenzoyl)amino]-4-methyl-1-[(phenylmethoxy)oxy]-2-azetidinone

To a cold (-10° C.) solution of(3S-trans)-3-amino-4-methyl-1-(phenylmethoxy)-2-azetidinone,toluenesulfonate (0.95 g; see example 2D) in methylene chloride (50 ml)is added 2,6-dimethoxybenzoyl chloride (0.60 g) and4-dimethylaminopyridine (0.61 g). The reaction is stirred under nitrogenand allowed to rise to 26° C. over five hours. The reaction mixture isconcentrated to an oil and partitioned between ethyl acetate and aqueoushydrogen sulfate solution. The organic layer is washed with aqueoussodium bicarbonate, and brine, dried over sodium sulfate andconcentrated to a foam (0.848 g).

(B)(3S-trans)-3-[(2,6-Dimethoxybenzoyl)amino]-1-hydroxy-4-methyl-2-azetidinone

To a stirred solution of(3S-trans)-3-[(2,6-dimethoxybenzoyl)amino]-4-methyl-1-[(phenylmethyl)oxy]-2-azetidinone(0.848 g) in absolute ethanol (20 ml) under nitrogen is added1,4-cyclohexadiene (8 ml) and freshly prepared palladium black(approximately 0.85 g). After one hour the reaction mixture is filteredand evaporated to a solid (0.605 g).

(C)(3S-trans)-3-[(2,6-Dimethoxybenzoyl)amino]-4-methyl-2-oxo-1-azetidinylsulfate, pyridine (1:1) salt

To a solution of(3S-trans)-3-[(2,6-dimethoxybenzoyl)amino]-1-hydroxy-4-methyl-2-azetidinone(0.60 g) in dry pyridine (20 ml) under nitrogen is added 4A molecularsieves (approximately 3 ml) and pyridine-sulfur trioxide complex (1.35g). After three hours the reaction mixture is filtered and the filtrateconcentrated and applied to an HP-20AG resin column (acetone/water). Thedesired fractions are lyophilized to afford the title compound (0.192 g)as a powder.

Anal. Calc'd. for C₁₈ H₂₁ N₃ SO₈.0.5 H₂ O: C, 48.21; H, 4.94; N, 9.37;S, 7.15. Found: C, 48.23; H, 4.94; N, 9.37; S, 7.10.

EXAMPLES 9-69

Following the procedure of example 3, but substituting the carboxylicacid listed in column I for(Z)-2-amino-α-(methoxyimino)-4-thiazoleacetic acid, yields the potassiumsalt of the compound listed in column II.

    __________________________________________________________________________    Column I                   Column II                                          __________________________________________________________________________     9.                                                                             (Z)-2-amino-α-(ethoxyimino)-4-                                                               [3S(Z)]-3-[[(2-amino-4-thiazolyl)(ethoxyimino)acety                           l]-                                                      thiazoleacetic acid  amino]-2-oxo-1-azetidinyl sulfate                      10.                                                                             (E)-2-amino-α -(methoxyimino)-4-                                                             [3S(E)]-3-[[(2-amino-4-thiazole)(methoxyimino)-          thiazoleacetic acid  acetyl]amino]-2-oxo-1-azetidinyl sulfate                 (Z)-2-amino-α-[ (2,2,2-trifluoro-                                                            [3S(Z)]-3-[[(2-amino-4-thiazolyl)[                                            (2,2,2-trifluoro-                                        ethoxy)imino]-4-thiazoleacetic acid                                                                ethoxy)imino]acetyl]amino]-2-oxo-1-azetidinyl                                 sulfate                                                  [(cyanomethyl)thio]acetic acid                                                                     (3S)-3-[[[(cyanomethyl)thio]acetyl]amino]-2-oxo-1-                            azetidinyl sulfate                                       1H-tetrazole-1-acetic acid                                                                         (3S)-3-[(1H-tetrazol-1-ylacetyl)amino]-2-oxo-1-                               azetidinyl sulfate                                       2-thiopheneacetic acid                                                                             (3S)-3-[ (2-thienylacetyl)amino]-2-oxo-1-azetidinyl                           1                                                                             sulfate                                                  (R)-α-[[(2-oxo-1-imidazolidinyl)                                                             [3S(R*)]-3-[[[[(2-oxo-1-imidazolidinyl)carbonyl]-        carbonyl]amino]benzeneacetic acid                                                                  amino]phenylacetyl]amino]-2-oxo-1-azetidinyl                                  sulfate                                                  (Z)-α-(methoxyimino)benzeneacetic                                                            [3S(Z)]-3-[[(methoxyimino)phenylacetyl[amino[-2-         acid                 oxo-1-azetidinyl sulfate                                 (Z)-2-amino-α-[[2-(diphenylmethoxy)-                                                         [3S(Z)]-3-[[(2-amino-4-thiazolyl)[[2-(diphenyl-          1,1-dimethyl-2-oxoethoxy]imino]-4-                                                                 methoxy)-1,1-dimethyl-2-oxoethoxy]imino]acetyl]-         thiazoleacetic acid  amino]-2-oxo-1-azetidinyl sulfate                        (Z)-2-amino-α-[[2-(diphenylmethoxy)-2-                                                       [3S(Z)]-3-[[(2-amino-4-thiazolyl)[[2-(diphenyl-          oxoethoxy]imino]-4-thiazoleacetic acid                                                             methoxy)-2-oxoethoxy]imino]acetyl]amino]-2-                                   oxo-1-azetidinyl sulfate                                 (D)-α-[[[(4-methoxyphenyl)methoxy]-                                                          [3S(D)]-3-[ [[[[(4-methoxyphenyl)methoxy]carbonyl]-                           5                                                        carbonyl]amino]-2-thiopheneacetic acid                                                             amino]-2-thienylacetyl]amino]-2-oxo-1-azetidinyl                              sulfate                                                20.                                                                             (±)-2-amino-α-[[[(4-methoxyphenyl)-                                                       [3S(±)]-3-[[(2-amino-4-thiazolyl)[[[(4-methoxy-                            .                                                        methoxy]carbonyl]amino]-4-thiazoleacetic                                                           phenyl)methoxy]carbonyl]amino]acetyl]amino]-2-           acid                 oxo-1-azetidinyl sulfate                                 (±)-α-[[[(4-methoxyphenyl)methoxy]-                                                       [3S(±)]-3-[[2-furanyl[[[(4-methoxyphenyl)methoxy                           ]-                                                       carbonyl]amino]-2-furanacetic acid                                                                 carbonyl]amino]acetyl]amino]-2-oxo-1-azetidinyl                               sulfate                                                  (L)-α-[[[(4-methoxyphenyl)methoxy]-                                                          [3S(L)]-3-[[[[[(4-methoxyphenyl)methoxy]carbonyl]-       carbonyl]amino]benzeneacetic acid                                                                  amino]phenylacetyl]amino]-2-oxo-1-azetidinyl                                  sulfate                                                  (L)-α-[[[(4-methoxyphenyl)methoxy]-                                                          [3S(L)]-3-[[[[[(4-methoxyphenyl)methoxy]carbonyl]-       carbonyl]amino]-2-thiopheneacetic acid                                                             amino]-2-thienylacetyl]amino]-2-oxo-1-azetidinyl                              sulfate                                                  (±)-α-[[(methylthio)thioxomethyl]thio]-                                                   (3S)-3-[[[[(methylthio)thioxomethyl]thio]phenyl-         benzeneacetic acid   acetyl]amino]-2-oxo-1-azetidinyl sulfate                 (D)-α-[[(4-ethyl-2,3-dioxo-1-piper-                                                          [3S(D)]-3-[[[[4-ethyl-2,3-dioxo-1-piperazinyl)-          azinyl)carbonyl]amino]-2-thiopheneacetic                                                           carbonyl]amino]-2-thienylacetyl]amino]-2-oxo-            acid                 1-azetidinyl sulfate                                     (±)-α-[[(methylamino)carbonyl]amino]-2-                                                   [3S(±)]-3-[[[[(methylamino)carbonyl]amino]-2-         thiopheneacetic acid thienylacetyl]amino]-2-oxo-1-azetidinyl sulfate          (35)-α-[(aminooxoacetyl)amino]-2-                                                            [3S(±)-3-[[[[(aminooxoacetyl)amino]-2-thienyl]-       thiopheneacetic acid acetyl]amino]-2-oxo-1-azetidinyl sulfate                 (R)-α-[[(4-ethyl-2,3-dioxo-1-                                                                [ 3S(R*)]-3-[[[[(4-ethyl-2,3-dioxo-1-piperazinyl)-       piperazinyl)carbonyl]amino]benzene-                                                                carbonyl]amino]phenylacetyl]amino]-2-oxo-1-              acetic acid          azetidinyl sulfate                                       (R)-α-[[[2-oxo-3-[(phenylmethlene)-                                                          [3S(R*)]-3-[[[[[2-oxo-3-[(phenylmethylene)amino]-        amino]-1-imidazolidinyl]carbonyl]amino]-                                                           1-imidazolidinyl]carbonyl]amino]phenylacetyl]-           benzeneacetic acid   amino]-2-oxo-1-azetidinyl sulfate                      30.                                                                             (R)-α-[[[3-(methylsulfonyl)-2-oxo-                                                           [3S(R*)]-3-[[[[[3-(methylsulfonyl)-2-oxo-1-              1-imidazolidinyl]carbonyl]amino]-                                                                  imidazolidinyl]carbonyl]amino]phenylacetyl]amino]-       benzeneacetic acid   2-oxo-1-azetidinyl sulfate                               (S)-α-hydroxybenzeneacetic acid                                                              [3S(S*)]-3-[(hydroxyphenylacetyl)amino]-2-oxo-1-                              azetidinyl sulfate                                       (R)-α-hydroxybenzeneacetic acid                                                              [3S(R*)]-3-[(hydroxyphenylacetyl)amino]-2-oxo-                                1-azetidinyl sulfate                                     (Z)-2-amino-α-[[(diethoxyphosphinyl)-                                                        [3S(Z)]-3-[[(2-amino-4-thiazolyl)[[(diethoxy-            methoxy]imino]-4-thiazoleacetic acid                                                               phosphinyl)methoxy]imino]acetyl]amino]-2-oxo-1-                               azetidinyl sulfate                                       (Z)-2-amino-α-[[2-(1,1-dimethylethoxy)-                                                      [3S(Z)]-3-[[(2-amino-4-thiazolyl)[[2-(1,1-dimethyl-      2-oxo-1-phenylethoxy]imino]-4-thiazole-                                                            ethoxy)-2-oxo-phenylethoxy]imino]acetyl]amino]-2-        acetic acid          oxo-1-azetidinyl sulfate                                 (Z)-2-amino-α-[(1H-tetrazol-5-ylmethoxy)-                                                    [ 3S(Z)]-3-[[(2-amino-4-thiazolyl)[(1H-tetrazol-5-       imino]-4-thiazoleacetic acid                                                                       ylmethoxy)imino]acetyl]amino]-2-oxo-1-azetidinyl                              sulfate                                                  (Z)-2-amino-α-[(phenylmethoxy)imino]-4-                                                      [3S(Z)]-3-[[(2-amino-4-thiazolyl)[(phenylmethoxy)-       thiazoleacetic acid  imino]acetyl]amino]-2-oxo-1-azetidinyl sulfate           (Z)-2-amino-α-[(2-amino-2-oxoethoxy)-                                                        [3S(Z)]-3-[[[(2-amino-2-oxoethoxy)imino](2-amino-        imino]-4-thiazoleacetic acid                                                                       4-thiazolyl)acetyl]amino]-2-oxo-1-azetidinyl                                  sulfate                                                  (Z)-2-amino-α-(hydroxyimino)-4-thiazole-                                                     [3S(Z)]-3-[[(2-amino-4-thiazolyl)(hydroxyimino)-         acetic acid          acetyl]amino]-2-oxo-1-azetidinyl sulfate                 α-sulfophenylacetic acid                                                                     (3S)-3-[(phenylsulfoacetyl)amino]-2-oxo-1-                                    azetidinyl sulfate                                     40.                                                                             (Z)-2-amino-α-[[2-(1,1-dimethylethoxy)-                                                      [3S(Z)]-3-[[(2-amino-4-thiazolyl)[[2-(1,1-dimethyl-      1-(methylthio)-2-oxoethoxy]imino]-4-                                                               ethoxy)-1-(methylthio)-2-oxoethoxy]imino]acetyl]-        thiazoleacetic acid  amino]-2-oxo-1-azetidinyl sulfate                        (Z)-α-(methoxyimino)-2-[[(phenylmethoxy)-                                                    [3S(Z)]-3-[[methoxyimino)[2-[[(phenylmethoxy)-           carbonyl]amino]-4-thiazoleacetic acid                                                              carbonyl]amino]-4-thiazolyl]acetyl]amino]-2-                                  oxo-1-azetidinyl sulfate                                 α-azidophenylacetic acid                                                                     (3S)-3-[(azidophenylacetyl)amino]-2-oxo-1-                                    azetidinyl sulfate                                       (S)-[[[2-oxo-3-(phenylmethylene)amino]-1-                                                          [3S(S*)]-3-[[[[[2-oxo-3-[(phenylmethylene)amino]-        imidazolidinyl]carbonyl]amino]-2-thio-                                                             1-imidazolidinyl]carbonyl]amino]-2-thienylacetyl]-       pheneacetic acid     amino]-2-oxo-1-azetidinyl sulfate                        (Z)-2-amino-α-[(1-diphenylmethoxy-                                                           [3S(Z)]-3-[[(2-amino-4-thiazolyl)[(1-diphenyl-           carbonyl-1-methylethoxy)imino]-4-                                                                  methoxycarbonyl-1-methylethoxy)imino]acetyl]-            thiazoleacetic acid  amino]-2-oxo-1-azetidinyl sulfate                        2-amino-α-[[2-(1,1-dimethylethoxy)-1-                                                        [3S(Z)]-3-[[[(2-amino-4-thiazolyl)[2-(1,1-               methyl-2-oxoethoxy]imino]-4-thiazole-                                                              dimethylethoxy)-1-methyl-2-oxoethoxy]imino]-             acetic acid          acetyl]amino]-2-oxo-1-azetidinyl sulfate                 (R)-α-[[(4-ethyl-2,3-dioxo-1-piper-                                                          [3S(R*)]-3-[[[[(4-ethyl-2,3-dioxo-4-piper-               azinyl)carbonyl]amino]-4-hydroxy-                                                                  azinyl)carbonyl]amino](4-hydroxyphenyl)acetyl]-          benzeneacetic acid   amino]-2-oxo-1-azetidinyl sulfate                        (±)-α-[[(4-ethyl-2,3-dioxo-1-piper-                                                       [3S(±)]-3-[[[[(4-ethyl-2,3-dioxo-4-piperazinyl)-      azinyl)carbonyl]amino]-2-furanacetic                                                               carbonyl]amino]-2-furanylacetyl]amino]-2-oxo-1-          acid                 azetidinyl sulfate                                       (R)-α-[[(4-ethyl-2,3-dioxo-1-piper-                                                          [3S(R*)]-3-[[1,4-cyclohexadien-1-yl[[(4-ethyl-           azinyl)carbonyl]amino]-1,4-cyclo-                                                                  2,3-dioxo-1-piperazinyl)carbonyl]amino]acetyl]-          hexadieneacetic acid amino]-2-oxo-1-azetidinyl sulfate                        (R)-α-[[[2,3-dioxo-4-[(phenylmethylene)-                                                     [3S(R*)]-3-[[[[[2,3-dioxo-4-[(phenylmethylene)-          amino]-1-piperazinyl]carbonyl]amino]-4-                                                            amino]-1-piperazinyl]carbonyl]amino](4-hydroxy-          hydroxybenzeneacetic acid                                                                          phenyl)acetyl]amino]-2-oxo-1-azetidinyl sulfate        50.                                                                             (Z)-2-amino-α-[(1-methylethoxy)imino]-4-                                                     [3S(Z)]-3-[[(2-amino-4-thiazolyl)[(1-methyl-             thiazoleacetic acid  ethoxy)imino]acetyl]amino]-2-oxo-1-azetidinyl                                 sulfate                                                  (Z)-2-amino-α-(phenoxyimino)-4-                                                              [3S(Z)]-3-[[ (2-amino-4-thiazolyl)(phenoxyimino)-        thiazoleacetic acid  acetyl]amino]-2-oxo-1-azetidinyl sulfate                 (R)-α-[[[3-[[(4-hydroxyphenyl)methyl-                                                        [3S(R*)]-3-[[[[[ 3-[[(4-hydroxyphenyl)methylene]-        ene]amino]-2-oxo-1-imidazolidinyl]-                                                                amino]-2-oxo-1-imidazolidinyl]carbonyl]amino]-           carbonyl]amino]benzeneacetic acid                                                                  phenylacetyl]amino]-2-oxo-1-azetidinyl sulfate           (R)-α-[[[2-oxo-3-[(4-pyridinylmethylene)-                                                    [3S(R*)]-2-oxo-3-[[[[[2-oxo-3-[(4-pyridinyl-             amino]-1-imidazolidinyl]carbonyl]amino]-                                                           methylene)amino]-1-imidazolidinyl]carbonyl]-             benzeneacetic acid   amino]phenylacetyl]amino]-1-azetidinyl sulfate           (Z)-2-amino-α-[[1-methyl-2-oxo-2-                                                            [3S(Z)]-3-[[(2-amino-4-thiazolyl)[[1-methyl-2-           (phenylmethoxy)ethoxy]imino]-4-                                                                    oxo-2-(phenylmethoxy)ethoxy]imino]acetyl]amino]-         thiazoleacetic acid  2-oxo-1-azetidinyl sulfate                               (Z)-2-amino-α-[(cyclopentyloxy)imino]-                                                       [3S(Z)]-3-[[(2-amino-4-thiazolyl)[(cyclopentyloxy)-      4-thiazoleacetic acid                                                                              imino]acetyl]amino]-2-oxo-1-azetidinyl sulfate           (R)-α-[[1-oxo-2-[[(phenylmethoxy)-                                                           [3S(R*)]-2-oxo-3-[[phenyl[[[[(phenylmethoxy)-            carbonyl]amino]ethyl]amino]benzeneacetic                                                           carbonyl]amino]acetyl]amino]acetyl]amino]-1-             acid                 azetidinyl sulfate                                       2-furanacetic acid   (S)-3-[(2-furanylacetyl)amino]-2-oxo-1-azetidinyl                             sulfate                                                  (R)-α-[[(2-oxo-3-phenyl-1-imidazol-                                                          (3S)-2-oxo-3-[[[[(2-oxo-3-phenyl-1-imidazolidinyl)-      idinyl)carbonyl]amino]benzeneacetic                                                                carbonyl]amino]phenylacetyl]amino]-1-azetidinyl          acid                 sulfate                                                  (R)-α-[[[2-oxo-3-(phenylmethyl)-1-                                                           [3S(R*)]-2-oxo-3-[[[[[2-oxo-3-(phenylmethyl)-1-          imidazolidinyl]carbonyl]amino]benzene-                                                             imidazolidinyl]carbonyl]amino]phenylacetyl]-             acetic acid          amino]-1-azetidinyl sulfate                            60.                                                                             (Z)-α-(methoxyimino)-2-furanacetic                                                           [ 3S(Z)]-3-[[(2-furanyl)(methoxyimino)acetyl] -          acid                 amino]-2-oxo-1-azetidinyl sulfate                        (R)-α-[[[3-[[(dimethylamino)methyl-                                                          [3S(R*)]-3-[[[[[3-[[(dimethylamino)methylene]-           ene]amino]-2-oxo-1-imidazolidinyl-                                                                 amino]-2-oxo-1-imidazolidinyl]carbonyl]amino]-           carbonyl]amino]benzeneacetic acid                                                                  phenylacetyl]amino]-2-oxo-1-azetidinyl sulfate           (R)-α-[[(3-ethyl-2-oxo-1-imidazol-                                                           [3S(R*)]-3-[[[[[(3-ethyl-2-oxo-1-imidazolidinyl]-        idinyl)carbonyl]amino]benzeneacetic                                                                carbonyl]amino]phenylacetyl]amino]-2-oxo-1-              acid                 azetidinyl sulfate                                       (R)-α-[[[[[(4-methoxyphenyl)methoxy]-                                                        [3S(R*)]-3-[[[[[[[ (4-methoxyphenyl)methoxy]-            carbonyl]amino]acetyl]amino]benzene-                                                               carbonyl]amino]acetyl]amino]phenylacetyl]-               acetic acid          amino]-2-oxo-1-azetidinyl sulfate                        (R)-α -[[[2-oxo-3-[[(phenylmethoxy)-                                                         [3S(R*)]-2-oxo-3-[[[[[2-oxo-3-[[(phenylmethoxy-          carbonyl]amino]-1-imidazolidinyl-                                                                  carbonyl]amino]-1-imidazolidinyl]carbonyl]amino]-        carbonyl amino benzeneacetic acid                                                                  phenylacetyl]amino]-1-azetidinyl sulfate                 (Z)-2-amino-α-[(2-amino-1,1-dimethyl-                                                        [3S(Z)]-3-[[[(2-amino-1,1-dimethyl-2-oxoethoxy)-         2-oxoethoxy)imino]-4-thiazoleacetic                                                                imino](2-amino-4-thiazolyl)actyl]amino]-2-oxo-           acid                 1-azetidinyl sulfate                                     (R)-α-[[[4-(1-methylethyl)-2,3-dioxo-                                                        [3S(R*)]-3-[[[[[4-(1-methylethyl)-2,3-                   1-piperazinyl]carbonyl]amino]-4-                                                                   dioxo-1-piperazinyl]carbonyl]amino](4-                   hydroxybenzeneacetic acid                                                                          hydroxyphenyl)acetyl]amino]-2-oxo-1-                                          azetidinyl sulfate                                       (R)-α-[[[3-(1-methylethyl)-2-oxo-                                                            [3S(R*)]-3-[[[[[3-methylethyl)-2-oxo-1-                  1-imidazolidinyl]carbonyl]amino]-                                                                  imidazolidinyl]carbonyl]amino]phenylacetyl]-             benzeneacetic acid   amino]-2-oxo-1-azetidinyl sulfate                        (Z)-2-amino-α-[[2-(diphenylmethoxy)-                                                         [3S(Z)]-3-[[(2-amino-4-thiazolyl)[[2-diphenyl-           1-methyl-2-oxoethoxy]imino]-4-                                                                     methoxy)-1-methyl-2-oxoethoxy]imino]acetyl]-             thiazoleacetic acid  amino]-2-oxo-1-azetidinyl sulfate                        5-methyl-3-phenyl-4-isoxazole-                                                                     (S)-3-[[(5-methyl-3-phenyl-4-isoxazolyl)-                carboxylic acid      carbonyl]amino]-2-oxo-1-azetidinyl                     __________________________________________________________________________                           sulfate                                            

EXAMPLE 70 2-Oxo-3-methoxy-3-[(phenylacetyl)amino]-1-azetidinyl sulfate,pyridine salt (A)3-Methoxy-3-[(phenylacetyl)amino]-1-[(phenylmethyl)oxy]-2-azetidinone

To a solution of(S)-3-[(phenylacetyl)amino]-1-[(phenylmethyl)oxy]-2-azetidinone (1mM;see example 4B) in freshly distilled tetrahydrofuran (10 ml) at -78° C.is added via syringe a solution of lithium methoxide (3mM) in drymethanol (5 ml). After 5 minutes, t-butyl hypochlorite (130 μl) is addedand the mixture is stirred at -78° C. for 30 minutes. The reactionmixture is poured into 0.5 M monobasic potassium phosphate buffer andextracted with two 100 ml portions of methylene chloride. The combinedorganic extracts are dried over sodium sulfate and concentrated to anoily residue. The title compound is isolated by column chromatography asa racemate.

(B) 2-Oxo-3-methoxy-3-[(phenylacetyl)amino]-1-azetidinyl sulfate,pyridine salt

Following the hydrogenolysis and sulfation procedures described inexample 4, parts C and D, but utilizing3-methoxy-3-[(phenylacetyl)amino]-1-[(phenylmethyl)oxy]-2-azetidinone inplace of(S)-3-[(phenylacetyl)amino]-1-[(phenylmethyl)oxy]-2-azetidinone, yieldsthe title compound.

What is claimed is:
 1. A β-lactam having the formula ##STR46## whereinR₃ and R₄ are the same or different and each is hydrogen or alkyl and Yis benzyl or pivaloyl.